Soil Carbon Accumulation and Nutrient Availability in Managed and Unmanaged Ecosystems of East Tennessee

Abstract

Native woodlot and grassland systems have been converted to a managed turfgrass system with urbanization. Turfgrass systems increased carbon sequestration and nitrogen availability compared with row crop systems. Cool‐season (C3) turfgrasses improved soil physical and chemical properties more than warm‐season (C4) grasses. In the last two decades, urban and suburban lands grew by 34% in the United States, with 16 to 20 million ha maintained under turfgrass systems. Side‐by‐side comparison of turfgrass systems with other managed and unmanaged ecosystems have not been comprehensively conducted in the climate transition zone of the United States, despite the environmental significance of land use changes. Our objective was to determine the relative effects of C3 and C4 turfgrasses on soil organic carbon (SOC) accumulation and nutrient availability, in comparison with managed row crop and unmanaged woodlot and grassland systems. Soil samples from depths of 0 to 5, 5 to 15, and 15 to 30 cm were collected during March 2017 at the University of Tennessee's East Tennessee Research and Education Center from seven ecosystems: (i) corn (Zea mays L.)–soybean (Glycine max L.) rotation, (ii) continuous soybean, (iii) tall fescue (Festuca arundinacea L.), (iv) Kentucky bluegrass (Poa pratensis L.), (v) bermudagrass (Cynodon dactylon L.), (vi) unmanaged grassland, and (vii) unmanaged woodlot. All turfgrass species were established in 2012 and were managed like low‐input residential lawns. Within the 30‐cm soil profile, turfgrass systems contained 4.2 kg m−2 SOC at the time of sampling, which was 33% more than croplands and 34% less than unmanaged systems, and the C4 turfgrass system contained 2.3 kg m−2 SOC and 0.4 mg kg−1 inorganic N, which were 56 and 57% lower than C3 systems, respectively. Results from this study highlight that low‐input lawns with suitable grass species can offer higher SOC stock and nutrient availability than conventional cropland systems.

Long‐term influence of phosphorus fertilization on organic carbon and nitrogen in soil aggregates under no‐till corn–wheat–soybean rotations

“…Camenzind et al (2016) observed 4.1% increase in water stable aggregates with P application rate of 10 kg ha −1 yr −1 than control in tropical ecosystem. Soil aggregation tends to increase SOC by influencing soil fertility and crop productivity by reducing erosion and controlling air permeability, water infiltration, and nutrient cycling (Singh et al, 2019b;Zhang et al, 2012). Soil aggregates are important agents of SOC retention (Haile, Nair, & Nair, 2008) by occluding C against microbial decomposition (Six, Elliott, & Paustian, 1999;Sollins, Homann, & Caldwell, 1996).…”

Cropping system management responses to Cornell and Alabama soil health assessment methods in the southeastern United States

“…Also, a sprinkler infiltrometer was used for WAS instead of commonly used wet sieving. Previous studies reported treatment differences in SOC and WAS from these tested cropping systems when dry combustion and wet sieving, respectively, were used (Nouri, Lee, Yin, Saxton, et al, 2019;Nouri, Lee, Yin, Tyler, et al, 2019;Singh et al, 2019;Singh, Nouri, et al, 2020). 2.…”

Koolstofvastlegging in grasvelden : Eindrapportage WP4 PPS Grasvelden, Klimaat & Biodiversiteit

“…C3 grassen veldbeemdgras en rietzwenkgras kunnen meer koolstof opslaan dan C4 gras bermudagras (Singh et al, 2019;Fransluebbers et al, 2002). Rietzwenkgras slaat weer meer koolstof op dan veldbeemdgras .…”